Please help!
Trapezoid ABCD is rotated 90° clockwise. What rule shows the input and output of the rotation, and what is the new coordinate of A′?

(x, y) → (−x, −y); A′ is at (5, −1)
(x, y) → (−y, x); A′ is at (−1, −5)
(x, y) → ( y, −x); A′ is at (1, 5)
(x, y) → (x, −y); A′ is at (−5, −1)